Is it possible to do a HTML todos list? I hear it requires database or some way of storing the info.

I want to Make a simple html page to manage Todos. It should have an input field. When the user enters text in the input field, show that input in the page. When an existing item is clicked, it should disappear from the page.

Code:
<!DOCTYPE html>
<html>
<head>
<script>
function addText(){
    var input = document.getElementById('post').value;
    document.getElementById('this').innerHTML += " " + input;
}
</script>
</head>
<body>

<p onclick='remove()' id="this"> </p>
<input type='text' id='post'/>
<input type='button' onclick='addText()' value='Enter Text'/>

</body>
</html>


Why is when I click the previous post it deletes the entire Paragraph instead of just one at time when click. and also once I delete something it doesn't allow me to re post
I want to make it so onclick with the mouse on the input text it deletes it from the rows and then allow me to repost something. someone help me please.